CCL5 and melanoma: CCL5 is released by both tumor cells and immune cells, including NK and T cells, and higher levels of CCL5 in melanoma patients correlate with significantly increased survival.186 Expression of CCL5 also correlates strongly and positively with that of NK cell markers in human melanoma tumors,186–188 and that association is very significant, as verified in other melanoma studies.189,190 Melanoma cells deficient in the growth factor progranulin show increased CCL5 expression and enhanced infiltration of NK cells but not T cells.